This invention relates, in general, to wire bonding and, more particularly, to wire bonding of nonparallel surfaces.
At the present time, conventional wire bonding is commonly done on integrated circuits between bonding pads of an integrated circuit and bonding tips of a leadframe. Typically, the bonding pads of the integrated circuit and the bonding tips of the leadframe are arranged such that a plane is capable of being drawn between the bonding pads and the bonding tips. However, in a worst case situation, either the bonding pads of the integrated circuit are lower than the bonding tips of the leadframe or the bonding tips of the leadframe are lower than the bonding pads of the integrated circuit, thus making the wire bond stepped between two different parallel planes.
However, as electronic interconnection becomes more complex, wire bonding between two sites that are not on parallel surfaces becomes necessary to achieve integration of the non-parallel surfaces. While the conventional process for wire bonding provides a method to wire bond sites that are of differing depths in parallel planes, the conventional bonding process does not provide a method for wire bonding to sites that are not in parallel planes.
It can be readily seen that conventional methods for wire bonding nonparallel surfaces have severe limitations. Also, it is evident that the conventional wire bonding processes are not capable of wire bonding nonparallel plane structures. Therefore, an apparatus and a method for bonding non-parallel plane structures would be highly desirable.